Disturbed sleep with night wandering has been identified as one of the most common symptoms leading to the institutionalization of the elderly, yet little is known of the etiology of this disorder. It may be related to excessive awakenings. Fragmented sleep at night and daytime napping are major problems for nursing home residents. Daytime sleepiness may be caused by nighttime fragmentation, by understimulation in the environment, by desynchronization of circadian rhythm related to inadequate illumination, or by a combination of two or more of these conditions. We propose to analyze 24-hour sleep patterns and illumination exposure of nursing home patients. Our specific aims are to 1) describe the 24-hour sleep patterns of nursing home patients using both EEG and actigraphic recordings, and cross-validate these methodologies; 2) characterize the associations between low illumination exposure and sleep fragmentation among nursing home patients; and 3) evaluate the effects of 2 interventions (activity therapy and phototherapy) designed to improve sleep patterns among nursing home patients. Each subject will be assigned to one of four groups: increased daytime stimulation and activity, bright light exposure in the evening (control group). Each group will have one week baseline, 2 week intervention, and one week post intervention follow-up. Data collected will describe the 24-hour sleep patterns, the sleep fragmentation and the illumination exposure of nursing home patients. The intervention trials will help determine whether the sleep fragmentation seen in the nursing home patients can be reduced and sleep consolidated by these approaches. The results will both help us understand the causes of sleep fragmentation and suggest practical treatment options.